液态结构与Al-Fe-Ce合金短程有序的相关性

采用Ｘ射线衍射技术研究了Ａｌ＿０．９Ｆｅ＿０．１和Ａｌ＿０．９Ｆｅ＿０．０５Ｃｅ＿０．０５合金的液态结构及Ａｌ＿０．９Ｆｅ＿０．０５Ｃｅ＿０．０５合金的非晶结构，并采用ＤＳＣ热分析研究了非晶合金的晶化行为．发现液态和非晶态合金的结构因子曲线上都存在明显的预峰，所对应的化学短程有序结构随温度降低，尺寸不断增大，但其结构单元的尺寸保持不变．Ｃｅ的加入使液态合金中化学短程有序及其结构单元的尺寸增大，并有利于原子间交互作用增强，从而提高非晶形成能力．预峰所对应的化学短程有序结构单元是以Ｆｅ原子为中心的二十面体准晶结构，这种结构在液态已形成，并保留在非晶中．

Correlation between Liquid Structure and the Chemical Short-range Order of Al-Fe-Ce Amorphous Alloy

The liquid structures of Al_0.9Fe_0.1 and Al_0.9Fe_0.05Ce_0.05 alloys and the microstructure of the Al_0.9Fe_0.05Ce_0.05 amorphous alloy have been studied by X-ray diffraction (XRD), and the crystallization behavior of the amorphous alloy has been investigated by differential scanning calorimetry (DSC). The distinct prepeaks have been found from the structure factors of the liquid and amorphous alloys. The structural size of chemical short-range order (CSRO) corresponding to the prepeak increases with decreasing temperature, but its siructural unit size remains constant. The addition of Ce can increase the structural size of CSRO and its unit size, and improve the interaction between atoms, so it is helpful to the Al-based glass formability. The structural unit corresponding to the prepeak is an icosahedral quasicrystalline structure with a Fe atom as the interstitial atom, and this structure has already formed in the liquid alloy and can be reserved in the amorphous alloy.